Refiners and other industrial manufacturers who add powdered catalyst additives to their processes at a rate of 20 lb/day or greater are well served by the technology available on the market today. In such applications, catalyst and additive suppliers normally supply their smallest standard addition system (for example, 50 ft3 (1.5 ton) capacity) such that the catalyst or additive are supplied to the industrial process in 1 ton tote bins, 1 ton supersacks, or open-topped 55 gallon drums. The catalyst or additive is most commonly transferred from these shipping containers into the addition system using a vacuum ejector built into the addition system, although pressurized and gravity unloading are practiced.
For processors who want to add less than about 20 lb/day, the above method is not practical. The weight resolution of the addition system is not sensitive enough, and shipping a 2,000 lb tote bin or supersack for a 10 lb/day application would mean ordering 200 days worth of catalyst or additive at a time. This is not cost effective.
Currently, industrial processors typically have two options to handle small quantities of catalyst or additives. One option is to receive the additive deliveries loose in open topped 55 gallon drums or 20-40 lb pails, and an operator would then need to scoop the additive out using a ladle or similar device, and add it to the process using a manual shot pot. Alternatively, industrial processors could receive the additive deliveries in pre-packaged plastic bags, typically containing between 1 lb to 5 lb each. These would be cut open by the operator using a knife, and added to the process using the same type of manual shot pot as above.
Unfortunately, both of these solutions have some significant drawbacks. Specifically, these processes lead to a lot of waste through accidental spillage, as the operator is often unable to completely empty loose material from the shipping containers, or the bags cannot be emptied completely, or are partially spilled when opened incorrectly. The catalyst and additives that are added in small amounts are typically very expensive (between $25 and $75 per lb) and so any such losses can be of significant financial consequence.
In addition, these processes have a high risk of exposing the operator to high levels of ambient dust. This is unavoidable due to the high level of close proximity manual handling involved. This requires the operator to wear extra protective equipment, which is time consuming to don and often uncomfortable to wear in hot climates. For this reason, such operations are not always done as per procedure, causing an uncontrolled health risk.
An additional problem is that there is no automatic recording of how much of these expensive additives are used. The industrial processor has to rely on written operator logs, which are notoriously poorly kept. This causes several more problems for the processor because assessing the effectiveness of these additives requires detailed knowledge of when they were added, and how much was added. Without this, the processor cannot assess if the additive is working correctly, or whether a newer version is really as effective as expected, thereby justifying a higher price (for example). Also, there is no automatic inventory control, which means that stocktaking must be done manually. Additives used in small amounts like this are frequently neglected, and so the processor frequently runs out, causing a need for emergency express deliveries at exorbitant cost.
Some processes require additions to be made in small amounts every few hours for maximum process stability. Relying on an operator to do this is risky, as people have a habit of forgetting to add, or not going out to do this in inclement weather. With paper records it is impossible to prove what happened either way.
The FCC process requires careful monitoring to ensure maximum reliability. Excessively high temperatures in the regenerator are a frequent cause of premature shutdowns, which typically cost millions of dollars per. day. Monitoring these temperatures without knowing the amount of catalyst or additive being added to control them is at best only partially effective, and so this lack of automatic monitoring of additive additions puts the process at increased risk of high financial losses from premature shutdowns.
It is therefore desirable to attain an improved method and addition system to add small amounts of catalyst and additives into industrial processes, including the FCC process. We have discovered a new addition system and method to add catalyst and additives into the industrial processes.